Basf Aktiengesellschaft

Klaus Pandl

Manfred Patsch

Joerg L Jessen

Bernd Siegel

Hermann Loeffler

Claus Marschner

Wolfgang Krause

Werner Aquila

Melanie Brunner

Hartwig Fuchs

J&ouml;rg Botzem

Ulrich Sch&auml;fer-L&uuml;derssen

Helmut Hagen

Martin Fischer

Matthias Wiesenfeldt

Jacques Dupuis

Matthias Dust

Eckehard Danz

Matthias Niedenbrueck

Uwe Nahr

Friedrich Wirsing

Siegel Bernd

The claimed invention relates to a process for preparing an aqueous formaldehyde solution comprising absorbing a formaldehyde-loaded gas stream, in an absorption zone, in an aqueous solution comprising from 0.000% to 0.01% by weight of a Bronsted base, based on the formaldehyde absorbed. The produced aqueous formaldehyde solution comprises: a) from 10 to 75% by weight of formaldehyde, b) from 0 to 500 ppm by weight of tetroxane, c) from 50 to 400 ppm by weight of formic acid, based on the formaldehyde absorbed, and d) from 0.2 to 5.0% by weight of methanol, based on the formaldehyde absorbed.

Aqueous formaldehyde solutions with a low tetroxane content

The process for the preparation of carbonyl compounds of the formula I

Process for the preparation of &agr;-diketones from ketols or ketals from ketols

A process for preparing metal aminoformazans by alkaline hydrolysis of the corresponding acylated amino derivates in aqueous medium, is described, the hydrolysis being carried out at from 120.degree. to 170.degree. C. and from 3 to 5 bar in the presence of from 1.5 to 3 mol of an alkali metal hyroxide, based on 1 mol of acylated aminoformazan.

Preparation of aminoformazans

Nitroanilinesulfonic acids of the formula ##STR1## where R is C.sub.1 -C.sub.4 -alkyl are prepared by sulfonation of 3-nitro-N-alkylanilines using oleum, and are reduced to 3-(N-alkylamino)aniline-4-sulfonic acids.

Nitroanilinesulfonic acids and the preparation of

Reactive dyes of the formula ##STR1## where l is 0 or 1,

Reactive dyes with two or three nitrogen-containing haloheterocycles as

Reactive dyes useful for dyeing or printing hydroxyl- or nitrogen-containing substrates have the formula ##STR1## where U is vinyl, propenyl or the radical of the formula ##STR2## in which Z.sup.1 is hydrogen or methyl and Z.sup.2 is a group which is detachable under alkaline reaction conditions,

Reactive dyes with a reactive system based on alkenylsulfonyl and benzyl

Reactive dyes useful for dyeing or printing hydroxyl- or nitrogen-containing substrates have the formula ##STR1## where Rg is a radical of the formula ##STR2## Ar is the radical of a benzene or naphthalene ring, Z.sup.1 and Z.sup.2 are each hydrogen, substituted or unsubstituted C.sub.1 -C.sub.4 -alkyl, substituted or unsubstituted phenyl, C.sub.1 -C.sub.4 -alkoxy, carboxyl, C.sub.1 -C.sub.4 -alkoxycarbonyl, cyano, halogen or hydroxysulfonyl,

Reactive dyes having an allylsulfonyl or propargylesulfonyl group

Double attachment reactive dyes have the formula ##STR1## where U.sup.1 is C.sub.1 -C.sub.4 -alkyl, phenyl, C.sub.2 -C.sub.10 -alkenyl or the radical ##STR2## where Q.sup.1 and Q.sup.2 are each independently of the other hydrogen or C.sub.1 -C.sub.4 -alkyl and Q.sup.3 is a group which is detachable under alkaline reaction conditions,

Double attachment reactive dyes having alkyl- or alkenylsulfonyl and

Phenylene diamines of the formula ##STR1## in which R.sup.1 denotes hydrogen, formyl or oxalyl,

Phenylene diamines and process for the preparation of phenylene diamines

A process for the preparation of 4-sulfonated anthranilic acids by sulfonation of ortho-nitrotoluenes with chlorosulfonic acid or oleum followed by oxidation of the methyl group and, finally, reduction of the nitro group.

Process for the preparation of sulfonated anthranilic acids

Reactive dyes of the formula ##STR1## where R.sup.1 is hydrogen, methyl or ethyl,

Doubled reactive dyes

Reactive dyes of the formula ##STR1## where 1 is 0 or 1,

Phenylsulfones of the formula ##STR1## in which R.sup. is hydrogen, halogen, C.sub.1 -C.sub.4 -alkyl, nitro, hydroxysulfonyl, carboxyl,

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Ludwigshafen, Germany

Klaus Pandl